The invention describes polymers for use in dielectric applications and, more particularly, to high-dielectric norbornylene-based polymers used in dielectric applications.
Capacitors, which basically include two electrodes separated by a dielectric material, are used in a wide variety of electrical applications to accumulate and store an electrical charge. The development of electronic devices and circuits of reduced size has led to a need for significantly smaller capacitors having increased capacity per unit volume and high temperature capabilities.
Recently much research has focused on the development of new polymer dielectric materials for next generation capacitors that may find use in the inverters of next generation hybrid electric vehicles (HEV). Capacitors used in HEVs inverters will be required to operate at 150° C., 600V, and have an energy density of 0.9 J/cm3. Polymer based thin film capacitors are ideal for this application due to their relatively high energy density, low cost, and high dielectric breakdown field. Perhaps one of the most beneficial attributes of thin polymer film based capacitors is their propensity to fail gracefully open rather than short. Currently polymer film capacitors rely on polymers with dielectric constants ranging from 2-3.5. The current polymer based capacitors have ceiling operational temperatures of between 105° C. and 120° C. because as the polymer dielectric temperature rises typically the dissipation factor increases above a usable value.
Useful would be polymer films with dielectric constants greater than approximately 3 and with low dissipation factors that can operate at elevated temperatures greater than 120° C.